getting close

Actually, I'm finally ready to start writing the code for mvhere, having completed and tested the mvhere form and the applicability rules.

Its taken a while, as this is the first dual context command I've worked on and of course, nested frames are new too.

The actual mvhere command should be easy--its a simplification of the mv command, without all the checking that is handled in the mvhere applicability rule. (Applicability has gotten pretty complex. Fortunately the work is done for the user in the basic interface--if the command is not applicable, the command is dimmed. On the other hand, with the advanced interface, the user gets an error message after trying the command, or the user can first check the various helps to see which commands are applicable.)